In the present study, the experiments were investigated the effects of different concentrations of
cryoprotective agents, such as NaHCO3, MgSO4, sodium ascorbate, sodium glutamate, phosphate buffer,
respectively, which used on survival of Lactobacillus bulgaricus during freeze drying. The number of viable cells
and survival ratio were measured by the plate count method. The results were as follows: cryoprotective agents
played important roles in survival of Lactobacillus bulgaricus during freeze drying. When the relative volume of
phosphate buffer was 1.5 (v/v), the number of viable cells was highest, while the survival ratio reached highest, the
concentration of sodium ascorbate was 4.5%.